Work machine with an adaptive control system and method for grade control

ABSTRACT

An adaptive control system automatically controls an attachment position during a grading operation of a surface. The system comprises a frame, an attachment, first sensor, a second sensor, a laser receiver and a controller. The first sensor generates a first sensor signal indicative of an angle of the frame. The second sensor generates a second sensor signal indicative of an angle of the ground-engaging attachment. The laser receiver receives a laser signal from a laser beacon and generates a height signal based on the laser signal. The height signal is indicative of a position of either the attachment or the frame relative to the laser signal. The controller establishes a target grade based on a desired grade of the surface; identifies a position of the attachment; receives the first sensor signal; the second sensor signal; and the laser signal. The controller generates a first control signal or second control signal based on the inputs.

TECHNICAL FIELD

The disclosure generally relates to an adaptive control system and method for a work machine with grade control.

BACKGROUND

Grading operations with work machines is a specialized phase of the construction process. Proper ground preparation ensures expected outcomes in architectural construction, control of water runoff, road construction, environmental impact and compliance with land grading standards. When using laser grading systems, objects may temporarily disrupt communications between a laser beacon located external to the work machine and the laser receiver on a work machine. Therein lies an opportunity for improved grade control for continued performance.

SUMMARY

An adaptive control system and method for a work machine is disclosed. The adaptive control system automatically controls an attachment position during a grading operation of a surface. The system comprises a frame, an attachment, first sensor, a second sensor, a laser receiver and a controller. The first sensor is configured to generate a first sensor signal indicative of an angle of the frame relative to the direction of gravity. The second sensor is configured to generate a second sensor signal indicative of an angle of the ground-engaging attachment relative to one of the frame and the direction of gravity. The laser receiver is configured to receive a laser signal from a laser beacon. The laser receiver generates a height signal based on the laser signal wherein the height signal is indicative of a position of either the attachment or the frame relative to the laser signal. The controller has a non-transitory computer readable medium with a program instruction to grade the surface. The program instructions when executed causes a processor of the controller to establish a target grade based on a desired grade of the surface; identify a position of the attachment with respect to the frame, the surface, or the laser signal; receive the first sensor signal from the first sensor; receive the second sensor signal from the second sensor; and receive the laser signal from the laser beacon. The processor may generate a first control signal based on the height signal. The first control signal actuates the + to maintain the attachment at a position corresponding to the target grade as the work machine propels. The processor may generate a second control based on either the first sensor signal or the second sensor signal in the absence of the height signal. The second control signal causing one or more actuators coupling the attachment to the work machine to maintain the attachment at a position corresponding to the historical value of a grade profile of the attachment as the work machine propels.

The laser receiver may comprise of a first receiver and a second receiver, wherein each receiver is located on a first laser mast and a second laser mast, respectively. The laser mast extends upwardly from a location fixed relative to the frame. The first receiver and the second receiver create a first height signal and a second height signal, respectively. The first height signal and the second height signal enable the controller to calculate the grade profile of the attachment. In the absence of either the first height signal or the second height signal, the controller may generate a third control signal based on the first sensor signal, the second sensor signal, and the remaining height signal.

The historical value may be derived in various ways. In a first embodiment, the running average is derived from a predetermined period of time. In a second embodiment, the running average is derived from a predetermined tolerance band. In a third embodiment, the running average is derived from a predetermined number of passes. In a fourth embodiment, the running average is based on a sampling rate dependent on either a worksite condition or a job function.

The processor may further be configured to create a performance degradation alert signal for the grading operation after a predetermined period of time of the second control signal operating the one or more actuators.

The processor may further be configured to suspend auto control mode of maintaining the attachment for the grading operation after a predetermined time of the second control signal operating the one or more actuators.

The height signal automatically controls the height of the laser receiver to correspond to the height of the laser signal as the work machine propels.

The method of automatically controlling a position of an attachment on a work machine during a grading operation of a surface includes the following steps. In a first step, the method includes establishing a target grade to establish a desired grade of the surface. Next, the method includes identifying a position of the attachment with respect to one of the frame, the surface, and the laser signal. The method also includes receiving a first sensor signal from a first sensor, receiving a second sensor signal form a second sensor, receiving a laser signal from a laser beacon, and generating a height signal based on the laser signal received wherein the height signal is indicative of a position of one of the attachment and the frame relative to the laser signal. The first sensor signal is indicative of an angle of the frame relative to the direction of gravity. The second sensor signal is indicative of an angle of the ground-engaging attachment relative to one of the frame and the direction of gravity. The method then includes generating a first control signal based on the height signal wherein the first control signal causing one or more actuators coupling the attachment to the work machine to maintain the attachment at a position corresponding to the target grade as the work machine propels. The method then includes generating a second control signal based on one of the first sensor signal and the second sensor signal in the absence of the height signal. The second control signal operating the one or more actuators to maintain the attachment at a position corresponding to historical value a grade profile as the work machine propels.

The above features and advantages and other features and advantages of the present teachings are readily apparent from the following detailed description of the best modes for carrying out the teachings when taken in connection with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a side view of one embodiment of a work machine, shown as a skid steer.

FIG. 2 is a block diagram of the system architecture and the flow of the adaptive grade control system.

FIG. 3 is a flowchart of a method of automatically controlling an attachment on a work machine with the adaptive control system for grade control.

FIG. 4 is a logic flow diagram illustrating one embodiment of the adaptive control system for grading.

DETAILED DESCRIPTION

Those having ordinary skill in the art will recognize that terms such as “above,” “below,” “upward,” “downward,” “top,” “bottom,” etc., are used descriptively for the figures, and do not represent limitations on the scope of the disclosure, as defined by the appended claims. Furthermore, the teachings may be described herein in terms of functional and/or logical block components and/or various processing steps. It should be realized that such block components may be comprised of any number of hardware, software, and/or firmware components configured to perform the specified functions.

Terms of degree, such as “generally”, “substantially” or “approximately” are understood by those of ordinary skill to refer to reasonable ranges outside of a given value or orientation, for example, general tolerances or positional relationships associated with manufacturing, assembly, and use of the described embodiments.

In addition, as used herein, the term “or” is an inclusive “or” operator and is equivalent to the term “and/or,” unless the context clearly dictates otherwise. The term “based on” is not exclusive and allows for being based on additional factors not described, unless the context clearly dictates otherwise.

As used herein, unless otherwise limited or modified, lists with elements that are separated by conjunctive terms (e.g., “and”) and that are also preceded by the phrase “one or more of” or “at least one of” indicate configurations or arrangements that potentially include individual elements of the list, or any combination thereof. For example, “at least one of A, B, and C” or “one or more of A, B, and C” indicates the possibilities of only A, only B, only C, or any combination of two or more of A, B, and C (e.g., A and B; B and C; A and C; or A, B, and C).

As used herein, “controller” 10 is intended to be used consistent with how the term is used by a person of skill in the art, and refers to a computing component with processing, memory, and communication capabilities, which is utilized to execute instructions (i.e., stored on the memory 20 or received via the communication capabilities) to control or communicate with one or more other components. In certain embodiments, the controller 10 may be configured to receive input signals in various formats (e.g., hydraulic signals, voltage signals, current signals, CAN messages, optical signals, radio signals), and to output command or communication signals in various formats (e.g., hydraulic signals, voltage signals, current signals, CAN messages, optical signals, radio signals).

The controller 10 may be in communication with other components on the work machine 100, such as hydraulic components, electrical components, and operator inputs within an operator station of an associated work machine. The controller 10 may be electrically connected to these other components by a wiring harness such that messages, commands, and electrical power may be transmitted between the controller 10 and the other components. Although the controller 10 is referenced in the singular, in alternative embodiments the configuration and functionality described herein can be split across multiple devices using techniques known to a person of ordinary skill in the art. The controller 10 includes the tangible, non-transitory memory 20 on which are recorded computer-executable instructions, including an adaptive control algorithm. The processor 30 of the controller 10 is configured for executing the adaptive control algorithm 40.

The controller 10 may be embodied as one or multiple digital computers or host machines each having one or more processors, read only memory (ROM), random access memory (RAM), electrically-programmable read only memory (EPROM), optical drives, magnetic drives, etc., a high-speed clock, analog-to-digital (A/D) circuitry, digital-to-analog (D/A) circuitry, and any required input/output (I/O) circuitry, I/O devices, and communication interfaces, as well as signal conditioning and buffer electronics.

The computer-readable memory 20 may include any non-transitory/tangible medium which participates in providing data or computer-readable instructions. The memory 20 may be non-volatile or volatile. Non-volatile media may include, for example, optical or magnetic disks and other persistent memory. Example volatile media may include dynamic random-access memory (DRAM), which may constitute a main memory. Other examples of embodiments for memory 20 include a floppy, flexible disk, or hard disk, magnetic tape or other magnetic medium, a CD-ROM, DVD, and/or any other optical medium, as well as other possible memory devices such as flash memory.

As such, a method 300 may be embodied as a program or algorithm 40 operable on the controller 10. It should be appreciated that the controller 10 may include any device capable of analyzing data from various sensors, comparing data, making decisions, and executing the required tasks.

Referring now to the drawings, FIG. 1 illustrates a side view of a work machine 100, depicted as a skid steer with an attachment 105 operatively coupled to the work machine 100. It should be understood, however, that the work machine 100 could be one of many types of work machines, including, and without limitation, a skid steer, a backhoe loader, a front loader, a bulldozer, and other construction or agricultural vehicles with a grading capacity. The work machine 100, as shown, has a frame 110, having a front-end section, or portion, and a rear-end portion 125. The work machine 100 includes a ground-engaging mechanism 155 that supports the frame 110 and an operator cab 160 supported on the frame 110. The operator cab 160 is optional if the cab is operated remotely and/or autonomously. The ground-engaging mechanism 155 may be configured to support the frame 110 on a surface 135. The work machine 100 may be operated to engage the ground and cut and move material to achieve simple or complex ground features on the ground. As used herein, direction with regards to the work machine is the direction such as operator faces. The work machine may experience movement in three directions and rotation in three directions. Direction for the work machine may also be referred to with regard to longitude 45 or the longitudinal directions, latitude 50 or the lateral direction, and vertical 55 of the vertical direction. Rotations for the work machine may be referred to roll or the roll direction 60, pitch 65 or the pitch direction, and yaw 70 or the yaw direction or heading.

A power source is coupled to the frame 110 and is operable to move the work machine 100. The illustrated work machine 100 includes wheels, but other embodiments may include one or more tracks or wheels that engage the surface 135. In this exemplary embodiment, the ground-engaging mechanism 155 on the left side of the work machine 100 may be operated at a different speed, or in a different direction, from the ground-engaging mechanism 155 on the right side of the work machine 100.

Now referring to both FIGS. 1 and 2 , the work machine 100 comprises the boom assembly 170 coupled to the frame 110. The attachment 105 (may also be referred to as work tool) may be coupled at a forward portion of the boom assembly 170 (e.g. a blade) while the rear portion of the boom assembly 170 is pivotally coupled to the frame 110. The attachment 105 at the forward portion of the boom assembly 170 may be coupled through an attachment coupler (not shown), an industry standard configuration or a coupler universally applicable to many Deere attachments and several after-market attachments.

The boom assembly 170 of the exemplary embodiment, comprises a first pair of boom arms 175 (one each on a left side and a right side) pivotally coupled to the frame 110 and moveable relative to the frame 110 by a pair of boom hydraulic actuators (not shown). During a grading operation, the boom arms 175 remain stationary. The attachment coupler is coupled to a forward section of the boom arms 175 and are moveable relative to the frame 110 by a pair of pitch/lift actuators 185. The frame 110 of the work machine 100 further comprises an auxiliary port on the front-end portion of the work machine to couple one or more auxiliary hydraulic actuators (i.e. hydraulic actuators found on the attachment) to drive movement of or actuate auxiliary functions of an attachment. The attachment coupler (not shown) enables the mechanical coupling of the attachment 105 to the frame 110. The auxiliary port 195, contrary to the attachment coupler, enables the hydraulic coupling of angling hydraulic actuators 198 on the attachment 105 to the hydraulic system. The angling hydraulic actuators 198 on the attachment 105 (e.g. a dozer blade) includes a single tilt hydraulic actuator 187 and a pair of angling hydraulic actuators 198. The tilt hydraulic actuator 187 tilts the attachment 105 relative to the work machine 100, which may also be referred to as moving the attachment 105 in the direction of roll 60. That is, actuating the angling hydraulic actuators 198 (more specifically the tilt hydraulic actuator 187) actuates the attachment and tilts the attachment in a radial motion about the forward portion of the boom assembly 170. The pair of angling hydraulic actuators 198 allow for the attachment 105 to move in the direction of yaw 70 or angle the attachment 1050 relative to the frame 110 in the direction of yaw 70.

FIG. 2 is a block diagram of the system architecture of the work machine and the flow of the adaptive control system 200 for grade control. One known system for grade control is available from Deere & Company of Moline, Ill. as an Integrated Grade Control (IGC) system, which generally is a blade control system using the combination of sensor input (e.g. GPS) and stored data (e.g. maps). The IGC system may also allow for operator control of an initial position setting, such as an initial height of a blade attachment. The IGC system may also allow for a combination of operator and automated position control. For example, the angle of the blade attachment may be initially or continuously under the control of the operator via a user interface, and the tilt of the blade may be controlled automatically according to input from sensors and data storage.

The adaptive grade control system comprises a first sensor 205, a second sensor 210, a laser receiver 215, and a controller 10. The first sensor 205 is affixed to the frame 110 of the work machine 100 and configured to provide a first sensor signal 220 indicative of the movement and orientation of the frame 110. In alternative embodiment, the first sensor 205 may not be affixed directly to the frame 110 but instead be connected to the frame through intermediate components or structures. In these alternative embodiment, the first sensor 205 is not directly affixed to the frame 110 but is still connected to the frame at a fixed relative position so as to experience the same motion as the frame 110. The first sensor 205 is configured to generate a first sensor signal 220 indicative of an angle of the frame relative to the direction of gravity, an angular measurement in the direction of pitch 65. This first sensor signal 220 may be referred to as a frame inclination signal. The controller 10 may actuate an implement based on the frame inclination angle. The first sensor 205 may also be configured to provide a first sensor signal 220 or signals indicative of other positions or velocities of the frame 110, including, its angular position, velocity, or acceleration in a direction such as the direction of roll 60, pitch 65, yaw 70 or its linear acceleration in a direction such as the direction of longitude 45, latitude 50, and vertical 55. The first sensor 205 may be configured to directly measure inclination, measure angular velocity and integrate to arrive at inclination, or measure inclination and derive to arrive at angular velocity.

The second sensor 210 may provide a blade inclination signal, which indicates the angle of the blade relative to gravity 220. The second sensor 210 is configured to generate a second sensor signal 225 indicative of an angle of the ground-engaging attachment 105 relative to one of the frame 110 and the direction of gravity. The second sensor 210 is affixed to the attachment 105 (shown here as an exemplary embodiment as a blade). The second sensor 205, like the first sensor 205, may be configured to measure angular position (inclination or orientation), velocity, or acceleration, or linear acceleration. In alternative embodiments, the second sensor 210 may be configured to instead measure an angle of linkage, such as an angle between the boom assembly 170 and the frame 110, in order to determine a position of the attachment 105. In alternative embodiments, the second sensor 210 may not be directly affixed to the attachment 105 but may instead be connected to the attachment 105 through intermediate components or structures. In these alternative embodiments, the second sensor 210 is not directly affixed to the attachment 105 but is still connected to the attachment at a fixed relative position so as to experience the same motion as the attachment.

The laser receiver 215 is configured to receive a laser signal 235 from a laser beacon 237. The laser receiver 215 generates a height signal 240 based on the laser signal 235, wherein the height signal 240 is indicative of a position of one of the attachment 105 and the frame 110 relative to the laser beacon 237. Located on a laser mast 115 and by detecting the laser signal 235 from the laser beacon 237, the laser receiver 215 may be configured to monitor the height of the work machine 100 relative to the laser beacon 237. In one exemplary embodiment, the laser beacon 237 may be configured to deliver a laser signal 235 such as a low intensity laser beam that may be swept over a worksite to define a laser plane. The laser beacon 237 may be positioned at a preselected coordinate location with the worksite 245. The laser beam may define the laser plane above the worksite at a predetermined elevational position, with the laser plane being substantially parallel to a desired surface grade. The distance between the laser plane and the target grade may thereby establish an elevational coordinate position in the vertical direction 55.

The controller 10 has a non-transitory computer readable medium with a program instruction 40 to grade the surface 135 wherein the program instructions 40 when executed causes a processor 30 of the controller 10 to perform the following steps. The processor 30 will establish a target grade 305 based on a desired grade of the surface 135, and then identify a position of the attachment 105 with respect to one of the frame 110, the surface 135, and the laser signal 235. The processor 30 may then receive the first sensor signal 220 from the first sensor 205, receive the second sensor signal 225 from the second sensor 210, and receive the laser signal 235 from the laser beacon 237. The processor 30 may then generate a first control signal 335 based on the height signal 240 wherein the first control signal 335 causing one or more actuators 197 coupling the attachment to the work machine to maintain the attachment 105 at a position corresponding to the target grade 305 as the work machine 100 propels about a worksite 245. In the disclosed embodiment, the one or more actuators 197 comprises of the pitch or lift actuators 185, tilt hydraulic actuators 187, and angling hydraulic actuators 198. Other machines may include a different set of actuators coupling the attachment to the work machine, for operating linkage kinematics.

In the absence of the height signal 240, the processor 30 may generate a second control signal 340 based on one of the first sensor signal 220 and the second sensor signal 225 wherein the second control signal 340 causing one or more actuators 197 coupling the attachment to the work machine to maintain the attachment 105 at a position corresponding to historical value 284 of the grade profile 262 (such as cross slope and the mainfall) of the attachment 105 as the work machine 100 propels about a worksite. Mainfall may be the slope in the direction the work machine propels. In other embodiments, the second control signal 340 may be determined a number of ways aside from a historical value 284. The historical value 284 of the grade profile 262 comprises one of a snapshot in a current, an immediate past, a past point in time or alternatively a past period of time. In one embodiment, the second control signal 260 may be based on a filtered value, or a Kalman filter, or other sensor fusions. For example, in another embodiment the second control signal 260 may be based on an algorithm that tracks the slopes of the laser signal 235 (i.e. the laser plane) and the motion of the work machine 100, and then uses the first sensor 205 and the second sensor 210 (e.g. the IMUS) to predict the motion of the work machine relative to a tacked laser plane when the laser signal 235 is missing. Alternatively, the second control signal 340 may be based on one of the first sensor signal and the second sensor signal and the kinematics between the frame and the attachment to estimate and control the implement height deviation from the historical values of the laser plane through, for example, a Kalman filter.

In this particular embodiment, the laser receiver 215 comprises of a first receiver 275 and a second receiver 280, wherein each receiver is located on a first laser mast 115 and a second laser mast 115, respectively. The laser masts 115 extend upwardly from a location fixed relative to the frame 110. The first receiver 275 and the second receiver 280 create a first height signal 240 a and a second height signal 240 b, respectively. The first height signal 240 a and the second height signal 240 b enabling the controller 10 to calculate one or more of the attributes of a grade profile 262 (such as cross slope and the mainfall) of the attachment 105. If either of the first height signal 240 a and the second height signal 240 b is disrupted, the controller 10 will generate the second control signal 340 based on the first sensor signal 220, the second sensor signal 225, and the remaining height signal. The height signal (240 a, 240 b) may possibly automatically control the height of the laser receiver 280 to correspond to the height of a laser signal as the work machine 100 propels.

The historical value 284 may be derived from a predetermined period of time 285. The processor 30 will record output from the first sensor 205 and the second sensor 210 (e.g. cross slope and mainfall) by deriving a sequence of averages of successive given numbers over a duration of time, and thereby evening out short-term fluctuations and clarifying grade profile 262 trends (such as cross slope and mainfall for example). Alternatively, the historical value 284 may be derived from a predetermined tolerance band 286 and thereby ignoring any outliers. In another embodiment, the historical value 284 may be derived from a predetermined number of passes 287 the work machine makes when grading a surface 135. For example, a final pass over a surface may require a higher sampling rate than an initial pass.

The historical value 284 may be derived from a sampling rate dependent on either a worksite condition 287 or the job function 289. For example, an architectural grading may require large changes in the contours of a land area for housing development. Whereas landscaping or turf development may require setting a slope for to create a desired drainage flow using rough grading. Finish grading, such as putting the final touches on a surface by removing large chunks of soil, rocks, or debris, may require greater accuracy and therefore a larger sampling rate. These are few examples of multiple applications when acquiring a grade profile 262 running average using the first sensor 205 and the second sensor 210 in a grading operation.

The controller 10 may further be configured to suspend the auto control mode 438 of maintaining the attachment 105 at a position after a period of time when the second control signal 340 is operating the one or more actuators 197. If the laser receiver 215 continues to fail, by damage for example, or alternatively if the laser beacon 237 discontinues operation wherein a laser signal is no longer transmitted over an extended period of time, auto control mode 438 may be suspended. Alternatively, the controller 10 may notify the operator that performance has degraded and allowing for the operator to decide whether or not to interrupt grade control.

FIG. 3 discloses a flowchart of a method 300 of automatically controlling a position of an attachment 105 on a work machine 100 during a grading operation of a surface 135 where the attachment 105 is movably coupled to the frame 110 via a boom assembly 170. The method comprises the following steps. In step 305, the method includes establishing a target grade to establish a desired grade of the surface. Next in step 310, the method 300 requires identifying a position of the attachment 105 with respect to either the frame 110, the surface 135, and the laser signal 235. Subsequently, in step 315, the method 300 includes receiving a first sensor signal 220 from a first sensor 205 wherein the first sensor signal 220 is indicative of an angle of the frame 110 relative to the direction of gravity. Then, in step 320, the method 300 comprises receiving a second sensor signal 225 from a second sensor 210 indicative of an angle of the ground-engaging attachment 105 relative to one of the frame 110 and the direction of gravity. Next in step 325, a laser signal 235 from a laser beacon 237 is received. In step 330, the method 300 includes generating a height signal 240 based on the laser signal 235, wherein the height signal 240 is indicative of a position of one of the attachment 105 and the frame 110 relative to the laser signal 220. Then in step 335, the method 300 includes generating a first control signal 255 based on the height signal 240 wherein the first control signal 255 causes one or more actuators 197 coupling the attachment to the work machine to maintain the attachment 105 at a position corresponding to the target grade 305 as the work machine 100 propels about the worksite 245. Finally, in step 340, the method includes generating a second control signal 340 based on one of the first sensor signal 220 and the second sensor signal 225, in the absence of the height signal 240, wherein the second control signal 340 operates the one or more actuators 197 to maintain the attachment 105 at a position corresponding to historical value 284 of a grade profile (e.g. cross slope and mainfall) as the work machine 100 propels about a worksite 245.

Now turning to FIG. 4 a logic flow diagrams illustrating one embodiment of the adaptive control system for grade control 200 is shown. The system 200 includes a series of processing instructions or steps that are depicted in flow diagram form. The process begins at 410 wherein the grade profile 262 of the attachment 105 (e.g. cross slope and mainfall) is calculated. Individual inputs for step 410 include the first laser receiver 215 (also referred to as LR1) receiving a first laser signal 235 from a laser beacon in step 402, the second laser receiver 215 (also referred to as LR2) receiving a second laser signal 235 from the laser beacon 237 in step 404, a first sensor signal 220 from a first sensor 205 in step 406, and a second sensor signal 225 from a second sensor 210 in step 408. At step 410, during system setup, a user, operator, worksite plan, or other individual inputs of information associated with the grade control system 200, a target grade is entered. Step 410 also includes calculating historical value 284 of one or more of the grade profile 262 based on time 285, tolerance 286, number of passes 287, worksite condition 288, or job function 289. The information with respect to the grade profile 262 from the first sensor 205 and the second sensor 210 is stored in memory 20. In step 418, if the first laser receiver 275 is generating a height signal 240 a, the logic sets the value to true in step 422. However, if there is an obstruction or equipment failure leading to a lack of height signal generation, the logic sets the value to false in step 424. Similarly, in step 412, if the second laser receiver 280 (also referred to as LR2) is generating a height signal 240 b, the logic sets the value to true in 416. However, if there is a lack of height signal generation, the logic sets the value to false in step 414. In step 424, the logic determines whether the first laser receiver 275 and the second laser receiver 280 have a value of true. If they are both true, the logic moves to step 426, generating a first control signal 255 for the hydraulic system based on both height signals 240 for grade control. However, if either the first laser receiver 275 or the second laser receiver 280 has a value of false, a time counter begins in step 428. If the laser signal 235 is disrupted greater than a specified timeframe in step 432 and 436 (e.g. 60 seconds), either auto control mode is suspended or the operator is notified that performance is degraded 438. If the laser signal 235 is disrupted less than the specified timeframe in step 432 and 436 (e.g. 60 seconds), an alternate control signal is generated. In step 434, a second control signal 260 is generated if both the first 275 and second laser receiver 280 have a value of false wherein the second control signal 260 is based on the first sensor signal 220 and the second sensor signal 225. However, in step 440, if only one laser receiver has a false value and the other has a true value, a third control signal 440 is generated based on the laser receiver set to true and the alternate sensor signal.

The adaptive control system and method for grade control disclosed herein has certain advantages. Notably, the system can maintain accuracy and continuity of the grading operation, and thereby eliminating inefficiencies in the process. Furthermore, the system enables a work machine to run automated by eliminating blips in equipment function, without necessarily requiring an operator to be present in the work machine.

As used herein, “e.g.” is utilized to non-exhaustively list examples, and carries the same meaning as alternative illustrative phrases such as “including,” “including, but not limited to,” and “including without limitation.” As used herein, unless otherwise limited or modified, lists with elements that are separated by conjunctive terms (e.g., “and”) and that are also preceded by the phrase “one or more of” “at least one of,” “at least,” or a like phrase, indicate configurations or arrangements that potentially include individual elements of the list, or any combination thereof. For example, “at least one of A, B, and C” and “one or more of A, B, and C” each indicate the possibility of only A, only B, only C, or any combination of two or more of A, B, and C (A and B; A and C; B and C; or A, B, and C). As used herein, the singular forms “a”, “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. Further, “comprises,” “includes,” and like phrases are intended to specify the presence of stated features, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, steps, operations, elements, components, and/or groups thereof. 

1. An adaptive control system for a work machine for automatically controlling an attachment position during a grading operation of a surface, the adaptive control system comprising: a frame; an attachment movably coupled to the frame via a boom assembly; a first sensor configured to generate a first sensor signal indicative of an angle of the frame relative to the direction of gravity; a second sensor configured to generate a second sensor signal indicative of an angle of the ground-engaging attachment relative to one of the frame and the direction of gravity; a laser receiver configured to receive a laser signal from a laser beacon, the laser receiver generating a height signal based on the laser signal, the height signal indicative of a position of one of the attachment and the frame relative to the laser signal; and a controller having a non-transitory computer readable medium with a program instruction to grade the surface, the program instructions when executed causing a processor of the controller: establish a target grade based on a desired grade of the surface; identify a position of the attachment with respect to one of the frame, the surface, and the laser signal; receive the first sensor signal from the first sensor; receive the second sensor signal from the second sensor; receive the laser signal from the laser beacon; generate a first control signal based on the height signal, the first control signal causing one or more actuators coupling the attachment to the work machine to maintain the attachment at a position corresponding to the target grade as the work machine propels; and generate a second control signal based on one of the first sensor signal and the second sensor signal in the absence of the height signal, the second control signal causing one or more actuators coupling the attachment to the work machine to maintain the attachment at a position corresponding to a historical value of a grade profile of the attachment as the work machine propels.
 2. The adaptive control system of claim 1, wherein the laser receiver comprises of a first receiver and a second receiver, wherein each receiver is located on a first laser mast and a second laser mast, respectively, the laser masts extending upwardly from a location fixed relative to the frame.
 3. The adaptive control system of claim 2, wherein the first receiver and the second receiver create a first height signal and a second height signal, respectively, the first height signal and the second height signal enabling the controller to calculate a grade profile of the attachment.
 4. The adaptive control system of claim 3, wherein in the absence of one of the first height signal and the second height signal, the controller generates a third control signal based on the first sensor signal, the second sensor signal, and the remaining height signal.
 5. The adaptive control system of claim 1, wherein the historical value is derived from a predetermined period of time.
 6. The adaptive control system of claim 1, wherein the historical value is derived from one of a predetermined tolerance band and a predetermined number of passes.
 7. The adaptive control system of claim 1, wherein the historical value is based on a sampling rate dependent on one of a worksite condition and a job function.
 8. The adaptive control system of claim 1, wherein the processor is further configured to create a performance degradation alert signal for the grading operation after a predetermined period of time of the second control signal operating the one or more actuators.
 9. The adaptive control system of claim 1, wherein the processor is further configured to suspend an auto control mode of maintaining the attachment for the grading operation after a predetermined time of the second control signal operating the one or more actuators.
 10. The adaptive control system claim 1, wherein the height signal automatically controls the height of the laser receiver to correspond to the height of the laser signal as the work machine propels.
 11. The method of automatically controlling a position of an attachment on a work machine during a grading operation of a surface, the attachment movably coupled to the frame via a boom assembly, the method comprising: establishing a target grade to establish a desired grade of the surface; identifying a position of the attachment with respect to one of the frame, the surface, and the laser signal; receiving a first sensor signal from a first sensor, the first sensor signal indicative of an angle of the frame relative to the direction of gravity; receiving a second sensor signal from a second sensor, the second sensor signal indicative of an angle of the ground-engaging attachment relative to one the frame and the direction of gravity; receiving a laser signal from a laser beacon; generating a height signal based on the laser signal received, the height signal indicative of a position of one of the attachment and the frame relative to the laser signal; generating a first control signal based on the height signal, first the control signal causing one or more actuators coupling the attachment to the work machine to maintain the attachment at a position corresponding to the target grade as the work machine propels; and generating a second control signal based on one of the first sensor signal and the second sensor signal in the absence of the height signal, the second control signal causing one or more actuators coupling the attachment to the work machine to maintain the attachment at a position corresponding to historical value of a grade profile as the work machine propels.
 12. The method of claim 11, wherein the laser signal is received on a first receiver and a second receiver located on a first laser mast and a second laser mast, respectively, the laser masts extending upwardly from a location fixed relative to the frame.
 13. The method of claim 12, wherein the first receiver and the second receiver create a first height signal and a second height signal, respectively, the first height signal and the second height signal enabling the controller to calculate one of a grade profile of the attachment.
 14. The method of claim 13, wherein in the absence of absence of one of the first height signal and the second height signal, the method includes generating a third control signal based on the first sensor signal, the second sensor signal, and the remaining height signal.
 15. The method of claim 11, wherein the historical value is derived from a predetermined period of time.
 16. The method of claim 11, wherein the historical value is derived from one of a predetermined tolerance band and a predetermined number of passes.
 17. The method of claim 11, wherein the historical value is based on a sampling rate dependent on one of a worksite condition and a job function.
 18. The method of claim 11, wherein the method further comprises creating a performance degradation alert signal for the grading operation after a predetermined period of time of the second control signal operating the one or more actuators.
 19. The method of claim 11, wherein the method further comprises suspending auto control mode of maintaining the attachment at a position after a predetermined time of the second control signal operating the one or more actuators.
 20. The method of claim 11, wherein the height signal automatically controls the height of the laser receiver to correspond to the height of a laser signal as the work machine propels. 